Optical index and method for cameras and film processing

ABSTRACT

A small miniature camera employs as a primary operating mechanism a spring biased shutter bellcrank which is arranged so one of its arms or pawls operates a pivoted shutter blade and cooperates with the other pawl to conrol the film advance mechanism to prevent double exposure. Also, the disposition of the pawls is such that one of them may be employed to trigger impulse operated flash cubes in timed relationship with the shutter opened by the other pawl. To avoid complex indexing mechanisms within such a camera an optical indexing feature is provided which employs a separate light path to the edge of a film strip that is controlled by the shutter to mark the developed film strip with a reference mark for subsequent automatic film processing procedures.

This is a division, of Ser. No. 362,274, filed May 21, 1973which is adivision of Ser. No. 297,324, filed Oct. 13, 1972, now abandoned.

Low cost cameras, often referred to as box cameras, have been wellaccepted by the public in the past. However, such cameras, usually areunable to utilize current technology with regard to film speeds andflash cubes, particularly the new impulse operated flash cubes soldunder the trademark "Magicube", which do not require a battery tooperate them. Also these low cost cameras do not typically incorporatecommon features found in the more expensive cameras, such as doubleexposure shutter interlocks, and single level actuation for filmtransport and shutter cocking. Further they tend to be bulky andinconvenient to handle.

An object of the current invention is the provision of a smallinexpensive camera which is convenient to carry and also incorporatesmany of the desirable features of the more expensive cameras.

Another object is the provision of a low cost miniature camera which canoperate impulse fired flash cubes.

A further object is the provision of an optical indexing system forcameras which provides frame edge references alongside film negativeswithout complex gears, sprockets and the like in the camera, whereby afilm strip exposed therein can be automatically processed.

SUMMARY OF THE INVENTION

The above objects and advantages can be accomplished with a cameramechanism which includes: a body member having a lens system operable tofocus an image on a film framing window therein with an arcuate grooveintersecting the optical axis of the lens system; a shutter arm pivotedon the body member with a shutter blade which is received in the arcuategroove and biased so the blade closes the optical axis; a spring drivenshutter bellcrank with two pawls being pivoted in the body member andoperable to momentarily displace the shutter bar when tripped to openthe optical axis; and manually operated film transport means operable toadvance a film strip and cock the shutter bellcrank through engagementwith the pawls. The film transport may also include interlocks whichcooperate with the pawls to prevent transport reversal and doubleexposures. Further the body member may include a separate light path tothe edge of the framing window that is controlled by the shutter bladeto provide an edge reference on a film strip for automatic processing ofthe developed film strip.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective of the camera mechanism illustratingits principal components and showing a suitable case therefore withbroken lines;

FIG. 2 is a stepped side section along lines II--II of FIG. 3 of thecamera mechanism supported within a suitable case;

FIG. 3 is a stepped front section along lines III--III of FIG. 2 toillustrate the related details of the components of the cameramechanism;

FIG. 4 is a broken away elevation illustrating the separate light pathin the body for forming an edge reference on a film strip;

FIG. 5 is a broken away perspective with a developed portion of a filmstrip illustrating both the image negative and the edge reference formedthereon by utilizing the camera mechanism;

FIG. 6 is a side section of the lower half of the camera mechanismillustrated in FIG. 2 but with the shutter bellcrank in a cockedposition versus the tripped position shown in FIG. 2; and

FIG. 7 is a rear section through the camera mechanism illustrating theframing window and the aperture in one edge thereof for opticallyindexing a film strip.

FIG. 8 is a flow chart illustrating the steps involved in the developingand printing process using the camera defined in the application.

DESCRIPTION OF AN EMBODIMENT

In FIG. 1, most of the principal components of a camera 10 areseparately illustrated in the exploded view. The main component, a bodymember 11 is formed as a unitary molded structure on which the otherillustrated components are assembled. Generally this body member formsthe light-tight camera box (best shown in FIG. 2) that includes a frontobjective lens 12, a rear objective lens 13 separated by a diaphragm 15having a small aperture 14 therein aligned with the optical axis 16 ofthe resulting lens system.

With the lens system open an inverted image is focused in the plane ofan exposure or framing window 18, along the back of the body memberthrough a diverging light-tight rectangular tunnel 19 which extends fromthe rear lens 13 to the framing window, as can be seen in FIG. 2. Thesurface of the tunnel includes corrugations 20 in its surface whichprevents spurious light from being reflected onto the film plane of theframing windows from the sides of the tunnel. A flat backing plate 21 isurged against the framing window with the spring 22 to hold a portion ofthe film strip sandwiched between the edges of the framing window andthe plate in a flat plane for an exposure of an image focused thereon bythe lens system.

In order to use this lens system in a camera a shutter must be providedso that the optical axis thereof can be opened and closed. Toaccommodate a between-the-lens shutter an arcuate groove 23 is formed inthe body member 11 which intersects the optical axis of the lens systemjust behind the diaphragm 15 as best can be seen in FIGS. 1 and 2. Thegroove extends from the intersection point between lenses 12 and 13,toward one end of the camera body member to allow for extended travel ofa shutter blade disposed in the groove. The transmit time of the bladein the groove controls the shutter speed.

A shutter is formed with a shutter bar 24 which is pivoted on pin 25projecting from the side of the body member 11 and extends towards thefront of the camera to the arcuate groove 23 where a curved shutterblade 26 is mounted normal to the end of the shutter bar and extendsinto the groove, as best illustrated in FIG. 5. A biasing spring 27 isconnected to the shutter bar near its pivot and urges the bar to aposition so that the curved shutter blade closes the optical axis of thelens system. If the shutter bar is momentarily displaced against thespring tension it will open the optical axis, allowing the lens systemto focus an image on the exposure plane of the framing window 18.

To control the shutter blade 26, a multi-function shutter bellcrank 30is employed and is pivoted beneath the arcuate groove 23 by insertingits integral pivot pin 31 into a stepped bore 32 formed in the bodymember 11. The center bellcrank includes two angularly disposed arms orpawls which are herein described, as shutter pawl 34 and drive pawl 37.The shutter bellcrank is mounted so that the shutter pawl slides overthe top of the shutter bar but engages a raised ramp or cheek 35 formedon the surface of the shutter bar so that the stepped end 33 of thispawl will engage the cheek as the bellcrank pivots about its pivot pinin a direction causing the pawl to move against this cheek. Drive forthe shutter pawl is provided by the spring 27 which is connected to thestepped end 36 of the drive pawl of the shutter bellcrank and alsoconnected to the shutter bar, as previously described. Through thisarrangement only a single spring is needed to provide the proper springbias on these several moving parts.

As can be seen in FIG. 2, where the shutter bellcrank 30 is in a trippedcondition the end 36 of the drive pawl 37 abuts against a resilient stop38 formed on the body member and the end 33 of the shutter pawl islocated above cheek 35 on the shutter bar. Thus if the shutter bellcrankis rotated counterclockwise from the position illustrated, a rampedsurface of the cheek will lift the end of the shutter pawl as it slidesover the cheeks and moves to a position on the other side of the cheek,to cock the camera. The shutter pawl can be bifurcated as illustrated toreduce the force necessary to deflect its end as it is lifted by theramped surface. When the rotation proceeds to the point the bellcrankreaches a cocked position, a shutter catch 39, which is biased againstthe underside of the shutter pawl in the tripped condition, raises toprevent clockwise rotation of the bellcrank until this catch is manuallyreleased. The shutter catch 39 is controlled by a trip member 40 thathas a large apertured ring 41 which is received on the projecting end ofthe lens barrel 42 at the front of the member. As a result, rotationalmovement of this ring will cause the catch to disengage the shutter pawlwhen the apertured ring structure is rotated on the lens barrel. A flator wire spring 43 is connected tangentially to the apertured ring 41 andalso to the body member to provide the biasing to urge the catch intoengagement with the shutter pawl when it is in a cocked position. Thistrip structure is shown in plan in FIG. 3 and the catch thereof isengaged with the shutter pawl in the cocked condition shown in FIG. 6. Atrip button 44, that is accessible through an opening in the outercamera case 45 can be depressed to release the shutter pawl as theapertured ring rotates against the spring tension of the flat or wirespring.

Upon release of the shutter pawl by the catch the shutter bellcrankrotates clockwise from the position shown in FIG. 6, so that its end 33momentarily engages a surface of cheek 35 on the shutter bar 24 andkicks the latter in a direction to drive the shutter blade out ofalignment with the optical axis whereby the lens system of the camera isopened. After this engagement with the cheek the shutter pawl continuesits arcuate path to a tripped position where the cheek will not contactits end 33 as spring 27 returns the shutter blade to interrupt theoptical axis. This position, giving the required clearance, is obtainedwhen the drive pawl 37 hits the resilient stop 38 as shown in FIG. 2.The impulse induced to the shutter arm, will cause the shutter blade tohit the top of the arcuate groove 23 and bounce back with the aid ofspring 27 to close the optical axis as the end of the shutter pawlclears the cheek during this transit. The shutter blade is a ballisticmember but has its maximum speeds at the time the shutter blade opensthe optical axis and closes it. Therefore an image shift on the film dueto changes of the speed of the shutter blade in closing or opening theoptical axis does not occur. In order to change the speed of the shuttera stop can be placed in the arcuate groove 23 to limit the travel(transit time) of the shutter blade and thereby increase the speed ofthe shutter since its transit period will be reduced depending on wherethe stop is located in the arcuate groove. However, the shutter bladecannot be stopped until after the end 33 of the shutter crank hascleared the cheek, as described above, since otherwise the shutter wouldhang-up on the shutter pawl.

As it is an object of this camera to provide a system in which doubleexposure of negatives is prevented, the shutter bellcrank 30 is arrangedto be rotated from a tripped position to a cocked position as a filmstrip is wound from a film storage well 50 in the body member onto atake-up film drum 51 adapted to be received in the film take-up well 52also formed in the body member. By manually turning the film take-updrum a portion of the film strip will sequentially be pulled from thestorage well, across the framing window 18 and onto the outer surface ofthe drum. By controlling the cocking of the shutter bellcrank with thefilm take-up drum a double exposure of the film strip in the framingwindow can be avoided. This feature is possible by the cooperation ofraised radial ribs 53 formed on the exterior surface of a control disc54 which is affixed to the bottom of the film drum 51, so it rotatestherewith. In the embodiment shown, the four ribs are equally spaced onthe surface of the disc to form four equal quadrants and are furtherarranged to cooperate with the shutter pawl and the drive pawl of thebellcrank 30, as the disc rotates, to control film advance. Referring toFIG. 2, the shutter bellcrank is in the tripped position so that the endof the drive pawl 37 abuts on the stop 38. As the end 36 of the drivepawl is stepped inwardly towards the drive disc when the film drum is inits proper position, it can be seen that one of the ribs 53 liesdirectly under the drive pawl so that it is contiguous to the innerstepped wall of the end of this pawl. As a result, if the film drum isturned in the direction of arrow A this rib will engage the stepped walland prevent rotation of the film drum in this direction. Thus the filmstrip cannot be damaged by inadvertent reversal of the film drum.However, if the film drum is manually turned in the direction of arrow Ba rib on the disc adjacent to the outer end of the drive pawl willengage this end and rotate the bellcrank counterclockwise as this rib isadvanced against the pawl. A counterclockwise rotation of the shutterbellcrank is effected, indicated by arrow C, and continues until the ribforces the stepped end 36 of the drive pawl outboard of its outer endwhich allows the rib to slide under the raised central portion of thedrive pawl. At this point of rotation of the disc it can be seen thatthe stepped end 33 of the shutter pawl has moved so its inner steppedwall will engage the forward rib of this quadrant stopping furtherrotation of the disc. As this point of rotation of the film take-up drumhas been reached, catch 39 will have been disengaged from under theshutter pawl and will have raised to be in line with this pawl. Thus asthe rib which is driving the shutter bellcrank slides under its steppedend, the spring 27 will pull the bellcrank slightly in a clockwisedirection so the shutter pawl engages the catch and so that the wall ofthe stepped end 36 moves behind its contiguous rib thereby locking thedisc from being rotated in either direction until after the bellcrank istripped. The cocked position of the bellcrank is illustrated in FIG. 6wherein the abovedescribed inner lock of the ribs is best shown.

Another function of bellcrank 30 is the provision of the force and thetiming of the firing of impulse operated flash cubes that are mounted inthe film transport knob of the camera. Through the control of the filmwinding interval a proper flash cube registration with the front of thecamera is obtained. More particularly the small camera mechanism isdesigned to utilize miniature four-sided flash cubes sold under thetrademark "Magicube" that includes a small striker that is released by ashort mechanical impulse to fire a flash cube having a mercury fulminateprimer. As a result, batteries are not required for flash operation.

More particularly the hollow interior of the film drum 51 includes abayonet-type socket 60 for receiving such a flash cube (not shown). Ingeneral this socket includes a base 61 having four projecting prongs 62which are received in indexing slots in the tubular base of such a flashcube, as it is pushed into the socket, and ultimately engage a series ofnotches on this tubular base to locate it at the proper axial positionwithin the socket. A spring 63 which is supported on the pronged baseholds a socket cover 64 against the inner lip of the manual winding knob65, that includes a flange 66 which is received and sealed in the top ofthe film drum to complete the socket, which is best illustrated in FIG.3.

The socket cover 64 includes a central opening for the tubular base ofthe flash cube and four circumferentially spaced pertures 67, each ofwhich forms a guide for one end of an impulse pin 68, which has itsopposite end received in a separate aperture 69 in the control disc 54,previously described. Thus when an impulse operated flash cube isinserted into the socket and pushed inwardly depressing the cover, theimpulse pins will be received in the apertures in the cube for operatingthe striker mechanisms therein. These impulse pins are accuratelypositioned relative to the striker mechanism within the flash cube bythe pronged socket which controls the depth of insertion of the tubularbase of the flash cube and also by the proper selection of the length ofthe individual pins.

As can be seen in FIG. 3, the end of each impulse pin 68 extendsslightly above the exterior surface of the control disc 54, includes aramped surface and is closely adjacent to one of the ribs 53 thereon.Referring to FIG. 6, showing the bellcrank 30 in its cocked position, itcan be appreciated when the bellcrank rotates clockwise, as catch 39 isreleased, that the stepped end 36 of the drive pawl 37 will ride acrossthe ramp of the projecting end of the adjacent impulse pin, driving itinto the film drum and thus into the base of the inserted flash cube. Asa result, a striker within the cube will be lifted off its catch andfire the flash cube. Further, as the drive pawl engages the impulse pinit can be seen that the shutter bar 24 has already been displaced by theshutter pawl so that shutter blade 26 has opened the optical axis at theimpulse pin is actuated. Thus, the relative angular positioning of thetwo pawls of the shutter bellcrank, ensure a proper timed relationshipbetween the shutter and the firing of the flash cube. Further, it shouldbe noted that only one of the impulse pins is operated for each 90°rotational position of the control disc. The flash cube is properlyoriented in the socket by axial grooves on its tubular base, and sincethe socket will turn one-quarter turn after each flash, the next side ofthe cube will be in position to fire when the film is advanced.Therefore, for each flash picture, proper side of the flash cube isalways in registry with the front of the camera.

Another feture of the instant invention is related to a provision forindexing the edge of the film strip so that the individual negative canbe automatically located after the film strip is developed. This isimportant in small cameras since the cost of indexing the film strip forsubsequent processing is expensive and complicates the design of acamera. The particular indexing of this invention is a form of opticalmarking or notching. It is accomplished by the utilization of a separatelight path to one edge of the film strip which is parallel to theoptical axis of the lens system, but completely independent therefrom.In the instant embodiment a passage 70 is formed in the body member 11,along the shutter bar side of the lens system to form this separatelight path. This passage extends from the front of the camera and openson an edge 72 of the framing window 18 against which the film strip ispressed by the flat plate 21 holding it against the framing window.FIGS. 4, 5 and 7 illustrate portions of this structure and it can beseen that passage 70 also intersects the arcuate groove 23 and includesa simple lens 71 at the front of the camera to collect additional lightfor the optical indexing or notching function. As it is necessary toachieve a definite relationship between the exposed negative on the filmand the optical notch formed by this passage, the shutter blade 26includes a secondary blade 26a which controls the opening and closing ofthe passage 70 simultaneously with the opening and closing of theoptical axis 16 of the lens system. As a result, a small exposed dot isformed alongside the negative in a predetermined location (see FIG. 5).After the film is developed an optical scanner can locate the dot 73 andproperly position the negative 74 during printing. Also it should beappreciated that a developed film strip 75 is illustrated in FIG. 5, sothat the dot formed along the edge of the negative will be shown inrelationship to the optical indexing system from which it was produced.

Since the film strip advance distance on a film take-up drum changes dueto an increasing effective diameter, as turns of the film stripaccumulate thereon, the film advance distance is not constant eventhough the angular increment of the drum is constant when the drum isadvanced. Thus, with the optical pattern exposed on the edge of the filmstrip beside each negative, it can be used to accurately position eachnegative in a film processor for printing. This eliminates the need forsprockets and gearing in the camera to provide constant spacing betweennegatives exposed as the patterns exposed on the edge provide reliablepositioning even though the distance between the exposed negatives isnot constant.

A view finder 80 may be incorporated in the body member 11 and isillustrated in the drawings. It includes an objective lens 81 and anoptical tunnel 82 that opens into an aperture in the camera case and asecondary lens 83 located at the rear of the optical tunnel adjacent tothe eye piece 84 of the camera case. The optical axis of the view finderis parallel to the optical axis of the lens system, as can be seen andthe view finder is used in a conventional manner to aim the camera.

What is claimed is:
 1. A method of indexing and printing film stripsusing cameras having a lens system, a shutter controlling the openingand closing of the lens system and a film transport for successivelyadvancing portions of its film strip in non-uniform intervals across aframing window for sequential exposures and commercially availableautomatic printing equipment comprising the steps of exposing a limitedportion of an edge of a film strip within such a camera not within theframing window at non-uniform intervals through an independent lightpassage simultaneously with the exposure of the portion of said filmstrip within said framing window, developing said film strip to obtain anegative of said exposed portions of said film strip, optically sensingon said developed film strip with automatic equipment said negative ofsaid exposed limited portion on said edge of said developed film strip,and positioning said exposed portion of said developed film stripcontaining said negative which was within the framing window in aprinter in relationship to the information obtained by optically sensingsaid exposed limited portion, whereby said negative is automaticallypositioned in said printer for proper printing.